Bis-piperazides of trisubstituted hydroxyphenylalkanoic acids

ABSTRACT

The compounds are esters and amides of trialkylhydroxyphenylalkanoic acid having the formula   &lt;IMAGE&gt;   &lt;IMAGE&gt;  wherein R, R1 and R2 are independently lower alkyl or cycloalkyl groups, R3 is hydrogen, alkyl, cycloalkyl, alkylene, phenyl, phenyl substituted by alkyl groups, alkylthioethyl, thiobis-alkylene, alkyleneoxyalkylene, polyoxyalkylene or a polyvalent cyclic or acyclic hydrocarbon radical, R4 is hydrogen, lower alkyl, cycloalkyl, R5 is hydrogen, alkyl, phenyl, phenyl substituted with alkyl groups, alkylene, polyoxyalkylene or polyvalent cyclic or acyclic hydrocarbon radical, A is lower alkylene, m is 1 to 4 and n is 1 to 6.

This application is a divisional of copending application, Ser. No.682,237, filed May 3, 1976, now U.S. Pat. No. 4,049,713 granted 9/20/77,which in turn is a divisional of application Ser. No. 490,835, filedJuly 23, 1974, now U.S. Pat. No. 3,984,460, issued Oct. 5, 1976, whichin turn is a continuation-in-part of application, Ser. No. 400,745,filed Sept. 25, 1973, now abandoned.

DETAILED DISCLOSURE

This invention pertains to esters and amides of hinderedhydroxyphenylalkanoic acids and to organic materials normally subject tooxidative, thermal and UV light deterioration stabilized with said esteror amide compounds. More specifically, the compounds of this inventionare those having the formula F-1 or F-2: ##STR3## wherein

R, R¹ and R² are independently lower alkyl of 1 to 8 carbon atoms,cycloalkyl of 5 to 6 carbon atoms, provided that there are not more than2 cycloalkyl groups, or R¹ and R² together with a butylene chain which,together with the phenyl ring, form a tetrahydronaphthyl group, R³ ishydrogen, alkyl of 1 to 30 carbon atoms, cycloalkyl of 5 to 6 carbonatoms, alkylene of 2 to 12 carbon atoms, cycloalkylene of 5 to 8 carbonatoms, alkylene of 7 to 10 carbon atoms containing a cycloalkane groupin the chain, phenyl, phenyl substituted with alkyl groups, said alkylgroups having 1 to 18 carbon atoms, alkylthioethyl of 5 to 27 atoms inthe chain, thiobis-alkylene of 5 to 9 atoms in the chain,alkyleneoxyalkylene of 5 to 9 atoms in the chain, polyoxyalkylene of 8to 101 atoms or a polyvalent cyclic or acyclic hydrocarbon radical of 3to 10 carbon atoms, R⁴ is hydrogen, lower alkyl of 1 to 8 carbon atoms,cycloalkyl of 5 to 6 carbon atoms, R⁴ and R⁵ together form a piperazinylring incorporating both nitrogen atoms when m is 2, or the group##STR4##

R⁵ is hydrogen, alkyl of 1 to 24 carbon atoms, phenyl, phenylsubstituted with alkyl groups, said alkyl groups having 1 to 18 carbonatoms, alkylene of 2 to 18 carbon atoms, a polyvalent cyclic or acyclichydrocarbon radical of 3 to 8 carbon atoms or alkyleneoxyalkylene of 5to 9 carbon atoms in the chain,

A is a straight or branched lower alkylene having 1 to 8 carbon atoms,

m is an integer of 1 to 4, and

n is an integer of 1 to 6.

The R, R¹ and R² groups can be straight or branched lower alkyl groupshaving 1 to 8 carbon atoms as for example, methyl, ethyl, propyl, butyl,pentyl, heptyl or octyl. R, R¹ and R² can be cycloalkyl of 5 to 6 carbonatoms such as cyclopentyl or cyclohexyl.

Preferably R is a branched alkyl group of 3 to 8 carbon atoms such asisopropyl, sec-butyl, tert-butyl, sec-and tert-amyl, sec-and tert-hexyl,sec- and tert-heptyl or sec- and tert-octyl. Most preferably R istert-butyl.

R¹ and R² are preferably an alkyl group of 1 to 3 carbon atoms such asmethyl, ethyl and n-propyl. Most preferably R¹ and R² are methyl.

The R³ group can be alkyl of 1 to 30 carbon atoms such as methyl,n-butyl, n-octyl, n-dodecyl, n-octadecyl, n-tetracosanyl orn-triacontanyl. Preferably R³ is an alkyl group of 1 to 18 carbon atomssuch as n-dodecyl or n-octadecyl.

The R³ group also is cycloalkyl of 5 to 6 carbon atoms, preferablycyclohexyl.

R³ is also phenyl or phenyl substituted with alkyl groups, said alkylgroups having 1 to 18 carbon atoms. The substituents may be methyl,isopropyl, tert-butyl and tert-octyl. Substitution in the ortho or parapositions of the phenyl ring is especially preferred. Preferably R³ isphenyl substituted with alkyl groups having 1 to 2 carbon atoms and mostpreferably 1 to 8 carbon atoms such as two tert-butyl groups.

R³ can also be alkylthioethyl of 5 to 27 atoms in the chain and havingthe general structure --CH₂ CH₂ SR° where R° is alkyl of 2 to 24 carbonatoms such as n-octyl, n-dodecyl, n-octadecyl and n-tetracosanyl,preferably R³ is alkylthioethyl of 5 to 21 atoms in the chain where R°is 2 to 18 carbon atoms.

Where n is 2, R³ is alkylene of 2 to 12 carbon atoms such as ethylene,tetramethylene, 2,2-dimethylpropylene, hexamethylene, octamethylene ordodecamethylene. Preferably R³ is alkylene of 2 to 8 carbon atoms andmost preferably 2 to 6 carbon atoms.

R³ is cycloalkylene of 5 to 8 carbon atoms such as 1,3-cyclopentanediyl,1,4-cyclohexanediyl and 2,2,4,4-tetramethyl-1,3-cyclobutanediyl.Preferably R³ is 2,2,4,4-tetramethyl-1,3-cyclobutanediyl.

R³ can also be alkylene of 7 to 10 carbon atoms containing a cycloalkanegroup in the chain such as 1,4-cyclohexanedimethylene and1,5-cyclooctanedimethylene. Preferably R³ is 1,4-cyclohexanedimethylene.

R³ can also be thiobis-alkylene of 5 to 9 atoms in the chain such asthiodiethylene and thiodibutylene. Preferably R³ is thiodiethylene. R³is also alkyleneoxyalkylene of 5 to 9 atoms in the chain such asoxydiethylene, oxydibutylene and oxydi(1,2-propylene). Preferably R³ isoxydiethylene.

R³ can also be polyoxyalkylene of 8 to 101 atoms having the generalstructure --R°° (OR°°)_(n) -- where R°° is a straight or branched loweralkylene of 2 to 4 carbon atoms and h is 2 to 33. R°° is ethylene,1,2-propylene, 1,2-butylene and tetramethylene. Preferably R³ ispolyoxyalkylene of 8 to 11 atoms where R°° is ethylene and h is 2 to 3.Most preferably R³ is polyoxyethylene of 8 atoms.

Where n is 3 to 6, R³ is a polyvalent cyclic or acyclic hydrocarbonradical of 3 to 10 carbon atoms such as 1,2,3-propanetriyl,neopentanetriyl, neopentanetetrayl, 2,2-dimethyl-2,2-butanetriyl,2,2-dimethyl-1,2,2-pentanetriyl, 1,2,3,4,5,6-cyclohexanehexayl or1,2,3,4,5,6-hexanehexayl. Preferably R³ is a polyvalent acyclichydrocarbon radical of 3 to 7 carbon atoms and most preferably of 5 to 7carbon atoms.

R⁴ is lower alkyl of 1 to 8 carbon atoms such as methyl, ethyl, butyland octyl. Preferably R⁴ is lower alkyl of 1 to 4 carbon atoms. Mostpreferably R⁴ is methyl. R⁴ is also cycloalkyl of 5 to 6 carbon atoms,preferably cyclohexyl.

Where m is 2, R⁴ can be the group ##STR5## when diethylene triamine ortriethylene tetramine are used in the preparation of the amides offormula F-2.

R⁵ can be alkyl of 1 to 24 carbon atoms such as methyl, octyl, n-dodecylor n-tetracosanyl, preferably of 1 to 18 carbon atoms such asn-octadecyl.

R⁵ is also phenyl or phenyl substituted with alkyl groups, said alkylgroups having 1 to 18 carbon atoms. The substituents may be methyl,isopropyl, tert-butyl and tert-octyl with substitution preferably in theortho or para positions of the phenyl ring.

Where m is 2, R⁵ is alkylene of 2 to 18 carbon atoms such as ethylene,octamethylene and octadecamethylene. Preferably R⁵ is alkylene of 2 to12 carbon atoms such as ethylene, hexamethylene and dodecamethylene.

R⁵ can also be polyoxyalkylene of 8 to 11 atoms having the generalformula --R°° (OR°°)_(k) -- where R°° is a straight or branched loweralkylene of 2 to 4 carbon atoms and k is 2 to 3. R⁵ is preferablypolyoxyalkylene of 8 atoms where R°° is ethylene and k is 2.

Where m is 3 to 4, R⁵ is a polyvalent cyclic or acyclic hydrocarbonradical of 3 to 8 carbon atoms such as neopentanetetrayl,neopentanetriyl, 1,2,3-propanetriyl andcyclohexan-1,4-diyl-1,4-dimethylene.

A is a straight or branched lower alkylene of 1 to 8 carbon atoms suchas methylene, ethylene, 1,2-propylene, trimethylene, 1,1-butylidene,2-methyl-1,1-propylidene and 1,1-octylidene. Preferably A is a straightchain alkylene of 1 to 3 carbon atoms, that is, methylene, ethylene andtrimethylene, and most preferably is methylene or ethylene.

The integer m is 1 to 4 and preferably is 1 to 2.

The integer n is 1 to 6 and preferably is 1 to 4.

The esters of this invention are prepared via usual esterificationprocedures from a suitable alcohol and an acid of the formula ##STR6##or an acid halide or acid anhydride thereof. The higher alkyl esters canalso be prepared from the lower alkyl ester, especially the methyl esterof the above represented compounds, by transesterification with a higheralkanol. The above carboxylic acid derivatives which are then convertedto the compounds of this invention are made in known manner asrepresented by the following chemical reactions: ##STR7## In equation(1) above, other halogenating agents such as phosphorus trichloride,phosphorus pentachloride may also be used.

The lower alkyl ester of I, e.g., methyl, is conveniently made by anacid catalyzed reaction in the presence of the lower alcohol e.g.,methanol. ##STR8##

Where A is ethylene the lower alkyl ester, e.g., compounds II, areconveniently made by reaction of the starting phenol (IV) with acrylateesters, for example, as represented by reaction (3): ##STR9## where R⁶is hydrogen or lower alkyl of 1 to 6 carbon atoms and R³ is alkyl of 1to 30 carbon atoms. Processes of this type are disclosed for example inthe U.S. Pat. No. 3,247,240 (Apr. 9, 1966) and U.S. Pat. No. 3,364,250(Jan. 16, 1968).

Products of type III can also be made by reacting IV with acrylonitrileor a substituted acrylonitrile followed by alcoholysis of the nitrile asset out in the following reactions (4) and (4a): ##STR10## Reaction (4)is analogous to that disclosed in U.S. Pat. No. 3,121,732 (Feb. 18,1964) for example.

Carboxylic acids I, where A is methylene are conveniently made by thereaction sequence represented by reactions 5, 5a and 5b. ##STR11## whereM is an alkali metal such as sodium and potassium and R⁷ and R⁸ arelower alkyl of 1 to 8 carbon atoms or together make a morpholine orpiperidine ring. Preferably R⁷ and R⁸ are methyl. ##STR12## VIII is thenconverted to the ester stabilizers of this invention in known manner asoutlined above. Synthesis of compounds of types VI and VII are detailedin the examples.

Substitution of higher aldehydes such as n-butanal and n-octanal forformaldehyde in reaction 5 leads to the preparation of acids of formulaI where A is 1,1-alkylidene.

Acids of formula I can also be prepared by reaction of substitutedphenolate anions with appropriate halogenalkane carboxylic esters,amides or nitriles where A may be straight or branched alkylene of 2 to8 carbon atoms.

Amides of this invention are prepared in known manner for example, byreacting the carboxylic acid of formula I or an acid chloride oranhydride thereof with the appropriate amine. The higher alkanamides canalso be prepared from the lower alkyl ester of the acid of formula I byknown amidation procedures.

Most of the 2, 3, 6 trialkylated phenols contemplated for use asstarting materials to make the compounds of this invention are knowncompounds which are available commercially. If not availablecommercially, the synthesis of these starting phenols have beendisclosed or their synthesis is shown in the examples. Thus, thepreparation of for example, 2,6-diisopropyl-3-methyl phenol and2,6-di-tert-butyl-3-methyl phenol is disclosed in Japanese Pat.application No. 70 15,491. The preparation of 2,3-dimethyl-6-tert-butylphenol is disclosed by G. Parc in Revue de L'Institut Francais duPetrole Vol. XV, page 693 (1960).

The hindered hydroxyphenyl alkanoates and amides of this invention notonly have superior stabilizing properties, but exhibit resistance to gasfading in polymeric substrates such as polypropylene multifilamentknitted cloth to a high degree not shown by other antioxidants. Inaddition, the stabilizers of this invention confer superior processingstability to polymers, such as polypropylene, as well as beingextraction resistant. This combination of properties is particularlyimportant for textiles fabricated from synthetic polymers.

The hindered hydroxyphenyl alkanoates and amides of this invention arestabilizers of organic material normally subject to thermal andoxidative deterioration. Materials which are thus stabilized includesynthetic organic polymeric substances such as vinyl resins formed fromthe polymerization of vinyl halides or from the co-polymerization ofvinyl halides with unsaturated polymerizable compounds, e.g., vinylesters, α,β-unsaturated ketones, α,β-unsaturated aldehydes andunsaturated hydrocarbons such as butadienes and styrene; poly-α-olefins,polybutylene including copolymers of α-olefins such asethylene/propylene copolymer; dienes such as polybutadiene,polyisoprene, and the like, including copolymers with other monomers;polyurethanes and polyamides such as polyhexamethylene adipamide andpolycaprolactam; polyesters such as polyethylene terephthalates;polycarbonates; polyacetals such as polyethylene terephthalatepolyacetal; polystyrene, polyethylene oxide; and copolymers such asthose of high impact polystyrene containing copolymers of butadiene andstyrene and those formed by the copolymerization of acrylonitrile,butadiene and/or styrene; natural and synthetic rubbers such asethylene/propylene/diene copolymer (EPDM) and chlorinated rubber;polyphenylene oxide and copolymers.

Other materials which can be stabilized by the compounds of the presentinvention include lubricating oil of the aliphatic ester type, i.e.,di(2-ethylene) azelate and other synthetic ester lubricants,pentaerythritol tetracaproate, and the like; animal and vegetablederived oils, e.g., linseed oil, fat, tallow, lard, peanut oil, codliver oil, castor oil, palm oil, corn oil, cottonseed oil, and the like;hydrocarbon materials such as gasoline, mineral oil, fuel oil, dryingoil, cutting fluids, waxes, resins and the like, salts of fatty acidssuch as soaps and the like; and alkylene glycols, e.g.,β-methoxyethylene glycol, methoxytriethylene glycol, triethylene glycol,octaethylene glycol, dibutylene glycol, dipropylene glycol and the like.

The substrates of particular important are olefin polymers such aspolyethylene and polypropylene. Polypropylene is especially wellstabilized with the compounds of this invention.

In general, the stabilizers of this invention are employed from about0.01 to about 5% by weight of the stabilized composition, although thiswill vary with the particular substrate and application. An advantageousrange is from about 0.05 to about 2% and especially from about 0.1 toabout 1%.

For addition to polymeric substrates, the stabilizers can be blendedbefore polymerization or after polymerization, during the usualprocessing operations, for example. by hot-milling, the composition thenbeing extruded, pressed, or the like into films, fibers, filaments,hollow spheres and the like. The heat stabilizing properties of thesecompounds advantageously stabilize the polymer against degradationduring such processing at the high temperature generally encountered.The stabilizers can also be dissolved in suitable solvents and sprayedon the surface of films, fabrics, filaments or the like to provideeffective stabilization.

These compounds can also be used in combination with other additivessuch as sulfur-containing esters, e.g., distearyl β-thiodipropionate(DSTDP) in an amount of from 0.01 to 2% by weight of the organicmaterial, and the like, pourpoint depressants, corrosion and rustinhibitors, dispersing agents, emulsifiers, antifoaming agents, carbonblack, accelerators and other chemicals used in rubber compounding,plasticizers, color stabilizers, surface active agents, filler,di-andtri-alkyl- and -alkylphenyl phosphites, heat stabilizers, ultravioletlight stabilizers, antiozonants, dyes, pigments, metal chelating agents,dyesites and the like. Often combinations such as these, particularlythe sulfur containing esters, the phosphites and/or the ultravioletlight stabilizers will produce superior results in certain applicationsto those expected by the properties of the individual components.

The following formula represents co-stabilizers which are in certaininstances very useful in combination with the stabilizers of thisinvention: ##STR13## wherein R is an alkyl group having from 6 to 24carbon atoms; and n is an integer from 1 to 6. Especially usefulcompounds of this type are dilauryl β-thiodipropionate and distearylβ-thiodipropionate. The above co-stabilizers are used in the amount offrom 0.01 to 2% by weight of the organic material, and preferably from0.1 to 1%.

In addition to the above noted additives that can be employed incombination with the compounds of this invention, it is often especiallyadvantageous to employ also light stabilizers. The light stabilizers areused in the amount of from 0.01 to 5% by weight of the organic material,and preferably from 0.1 to 1%. Illustrative examples of lightstabilizers are listed below.

UV-Absorbers and light protection agents

2-(2'-hydroxyphenyl)-benztriazoles, such as, for example, the5'-methyl-, 3',5'-di-tert.-butyl-, 5'-tert.-butyl-,5'-(1,1,3,3-tetramethyl-butyl)-, 5-chloro-3', 5'-di-tert.-butyl-,5-chloro-3'-tert.-butyl-5'-methyl-, 3'-sec.-butyl-5'-tert.-butyl-,3'-{α-methyl-benzyl}-5'-methyl-,3'-{α-methylbenzyl}-5'-methyl-5-chloro-, 4'-hydroxy-, 4'-methoxy-,4'-octoxy-, 3',5'-di-tert.-amyl-, 3'-methyl-5'-carbomethoxyethyl- or5-chloro-3',5'-di-tert.-amyl-derivative.

2,4-bis-(2'-hydroxyphenyl)-6-alkyl-s-triazines, such as, for example,the 6-ethyl-, 6-undecyl- or 6-heptadecyl-derivative.

2-hydroxy-benzophenones, such as, for example, the 4-hydroxy-,4-methoxy-, 4-octoxy-, 4-decyloxy-, 4-dodecyloxy-, 4-benzyloxy-,4,2',4'-trihydroxy- or 2'-hydroxy-4,4'-dimethoxy-derivatives.

1,3-bis-(2'-hydroxy-benzoyl)-benzenes, such as, for example,1,3-bis-(2'-hydroxy-4'-hexyloxy-benzoyl)-benzene,1,3-bis-(2'-hydroxy-4'-octoxy-benzoyl)-benzene and1,3-bis-(2'-hydroxy-4'-dodecyloxy-benzoyl)-benzene.

Esters of optionally substituted benzoic acids, such as, for example,phenyl salicylate, octylphenyl salicylate, di-benzoylresorcinol,bis-(4-tert.-butyl-benzoyl)-resorcinol, benzoyl-resorcinol,3,5-di-tert.-butyl-4-hydroxybenzoic acid 2,4-di-tert.-butyl-phenylester, octadecyl ester or 2-methyl-4,6-di-tert.-butyl-phenyl ester.

Acrylates, such as, for example, α-cyano-β,β-diphenylacrylic acid ethylester or isooctyl ester, α-carbomethoxy-cinnamic acid methyl ester,α-cyano-β-methyl-p-methoxy-cinnamic acid methyl ester or butyl ester andN-(β-carbomethoxy-vinyl)-2-methyl-indoline.

Nickel compounds, such as, for example, nickel complexes of2,2'-thio-bis-4-(1,1,3,3-tetramethylbutyl)-phenol, such as the 1:1 and1:2 complex, optionally with other ligands such as n-butylamine,triethanolamine or N-cyclohexyl-diethanolamine; nickel complexes ofbis-{2-hydroxy-4-(1,1,3,3-tetramethylbutyl)-phenyl}-sulphone, such asthe 2:1 complex, optionally with other ligands such as 2-ethyl-caproicacid; nickel dibutyldithiocarbamate, nickel salts of4-hydroxy-3,5-di-tert.-butylbenzyl-phosphonic acid monoalkyl esters,such as the methyl, ethyl or butyl ester, the nickel complex of(2-hydroxy-4-methylphenyl)-undecyl-ketonoxime and nickel3,5-di-tert.-butyl-4-hydroxy-benzoate.

Oxalic acid diamides, such as, for example, 4,4'-di-octyloxyoxanilide,2,2'-dioctyloxy-5,5'-di-tert.-butyl-oxanilide,2,2'-di-dodecyloxy-5,5'-di-tert.-butyl oxanilide,2-ethoxy-5-tertiarybutyl-2'-ethyl-oxanilide,2-ethoxy-2'-ethyl-oxanilide, N,N'-bis-(3-dimethylaminopropyl) oxalamide,mixtures of o- and p-methoxy and o- and p-ethoxy-di-substitutedoxanilides and mixtures of 2-ethoxy-5-tert.-butyl-2'-ethyl-oxanilidewith 2-ethoxy-2'-ethyl-5,4'-di-tert.-butyl-oxanilide.

Sterically hindered amines, such as, for example4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy2,2,6,6-tetramethylpiperidine,bis-(2,2,6,6-tetramethylpiperidyl)-sebacate and3-n-octyl-7,7,9,9-tetramethyl-1,3-triaza-spiro[4,5]decane-2,4-dione.

For exemplification purposes only listed below are compounds of thisinvention which are useful as stabilizers as discussed above.

methyl 3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate

ethyl 3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate

n-butyl 3-(2,3,5-tri-methyl-4-hydroxyphenyl)-propionate

n-octyl 3-(5-t-butyl-2,3-diethyl-4-hydroxyphenyl)propionate

methyl 3-(2,3-dimethyl-5-t-octyl-4-hydroxyphenyl)propionate

methyl 3-(5,6,7,8-tetrahydro-4-hydroxy-3-butyl-naphthyl-1)propionate

n-octadecyl 3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate

2-(n-octadecylthio-)ethyl3-(5-t-butyl-2,3-di-methyl-4-hydroxyphenyl)propionate

2-(ethylthio-)ethyl3-(3,5-di-t-butyl-2-methyl-4-hydroxyphenyl)propionate

2-(n-octylthio-)ethyl 5-t-butyl-2,3-di-methyl-4-hydroxyphenylacetate

cyclohexyl 3-(5-t-butyl-2,3-dimethyl-4-hydroxy-phenyl)propionate

neopentanetetrayltetrakis(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)acetate

neopentanetetrayltetrakis{3-(5-t-octyl-2,3-dimethyl-4-hydroxyphenyl)propionate}

neopentanetetrayltetrakis{4-(5-t-butyl-2,3-diethyl-4-hydroxyphenyl)butyrate}

1,2,3,4,5,6-hexanehexaylhexakis[3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate}

1,2,3-butanetriyltris-{3-(5,6,7,8-tetrahydro-4-hydroxy-3-t-butylnaphthyl-1)propionate]

methyl 5-t-butyl-2,3-dimethyl-4-hydroxyphenylacetate

n-octadecyl 5-t-butyl-2,3-dimethyl-4-hydroxyphenylacetate

n-butyl 5-t-butyl-2,3-dimethyl-4-hydroxyphenylacetate

n-octyl 5-t-butyl-2,3-dimethyl-4-hydroxyphenylacetate

n-dodecyl 5-t-butyl-2,3-dimethyl-4-hydroxyphenylacetate

2,2-dimethylpropylenebis-(5-t-butyl-2,3-dimethyl-4-hydroxyphenylacetate)

1,6-hexamethylene bis-(5-t-butyl-2,3-dimethyl-4-hydroxyphenylacetate)

p-t-octylphenyl 3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate

phenyl 3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate

o-methylphenyl 3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate

o,p-di-t-butylphenyl3-(5-t-butyl-2,3-di-methyl-4-hydroxyphenyl)propionate

2-ethylhexyl 3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate

n-octadecyl 3-(2,3-dimethyl-5-t-octyl-4-hydroxyphenyl)propionate

n-octadecyl3-(5,6,7,8-tetrahydro-4-hydroxy-3-t-butylnaphthyl-1)propionate

2,2-dimethylpropylenebis-(5-t-octyl-2,3-dimethyl-4-hydroxyphenylacetate)

1,6-hexamethylenebis-[3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate]

1,2-propylene bis-[3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate]

ethylene bis-[3-(5-isopropyl-2,3-dimethyl-4-hydroxyphenyl)propionate]

2,2-dimethylpropylene bis-(5-t-octyl-2,3-diethyl-4-hydroxyphenyl)acetate

2,2-dimethylpropylenebis-[3-(5-cyclohexyl-2,3-dimethyl-4-hyroxyphenyl)propionate]

2-methyl-1,4-pentamethylene bis[3-(2,3,5-triethyl-4-hydroxyphenyl)propionate]

1,8-octamethylene bis-[4-(2,3,5-tri-t-butyl-4-hydroxyphenyl)butyrate]

2,4-dimethyl-2,4-pentamethylenebis-[6-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)hexanoate]

1,5-pentamethylenebis-[3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate]

1,12-dodecamethylene bis-[3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate]

2,2-dimethyl-1,2,2-butanetriyltris-[3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate]

1,2,3-propanetriyltris[3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate]

2,2-dimethyl-1,2,2-pentanetriyltris(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)acetate

neopentanetetrayltetrakis[3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate]

phenyl (5-t-octyl-2,3-dimethyl-4-hydroxyphenyl)-acetate

neopentanetriyl tris-(5-t-butyl-2,3-dimethyl-4-hydroxyophenylacetate)

thiodiethylene bis-(5-t-butyl-2,3-dimethyl-4-hydroxyphenylacetate)

thiodiethylenebis-[3-(5-t-butyl-2,3-di-methyl-4-hydroxyphenyl)propionate]

ethylene bis-[3-(5-t-butyl-2,3-di-methyl-4-hydroxyphenyl)propionate]

3,6-dioxa-1,8- octamethylenebis-[3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate]

2,2-dimethylpropylenebis-[3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate]

2,2-dimethyl-1,2,2-pentanetriyltris-[3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate]

1,4-cyclohexanedimethylenebis-[3-(5-tert-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate]

3-(5-tert-butyl-2,3-dimethyl-4-hydroxyphenyl)-propionamide

(5-tert-butyl-2,3-dimethyl-4-hydroxyphenyl)-acetamide

N-methyl-N-n-tetracosanyl-3-(2,3-dimethyl-5-tert-butyl-4-hydroxyphenyl)propionamide

N-n-octyl-N-phenyl-(5-tert-butyl-2,3-dimethyl-4-hydroxyphenyl)acetamide

N-cyclohexyl-3-(5-tert-octyl-2,3-dimethyl-4-hydroxyphenyl)propionamide

N,N-dibutyl-3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionamide

N,N',N",N'''-1,4-dimethylcyclohexan-1,1,4,4,-tetrayltetrakis[3-(5-tert-butyl-2,3-dimethyl-4-hydroxyphenyl)-propionamide]

N-o-tolyl-N-methyl-(5-tert-octyl-2,3-dimethyl-4-hydroxyphenyl)acetamide.

The following examples are illustrative of the invention, but are notmeant to limit the scope of same. In said examples, parts are by weightunless otherwise indicated and the relationship between parts by weightand parts by volume is as that between grams and cubic centimeters. Thetemperatures are in degrees centigrade.

EXAMPLE I Methyl3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate

1.53 grams of sodium metal was added in small pieces to 240.6 grams of2-tert.-butyl-5,6-dimethylphenol warmed at 60°. The reaction mixture wasthen heated at 120° with stirring for 2 hours, during which time thesodium metal was completely reacted. 174 grams of methyl acrylate wasthen added gradually over a period of 1 hour so that the temperature wasmaintained at 120°. The reaction mixture was then heated at 120° to 130°for an additional four hours. 3.9 ml. of acetic acid was then added. Thereaction mixture was diluted with 600 ml. of toluene and warmed todissolve a precipitate. The toluene solution was washed successivelywith 2N sodium carbonate, saturated sodium chloride, water, diluteaqueous hydrochloric acid and finally with water until the waterwashings were almost neutral. After drying over sodium sulfate, theclear toluene solution was evaporated at 20 mm Hg. pressure and finallyat 1 mm. Hg. pressure for two hours. The crude residual product wascrystallized from a mixture of 450 ml. of isopropanol and 200 ml. waterand kept at about 15° C overnight. The thick crystalline slurry wasfiltered, the filter cake being washed with a little coldisopropanol-water mixture. After drying and recrystallization, thedesired product was obtained as white crystals melting at 74° to 76° C(Compound 1).

EXAMPLE 2 Methyl3-(2,3-dimethyl-5-tert.-octyl-4-hydroxyphenyl)propionate

a. 2,3-Dimethyl-6-(1,1,3,3-tetramethylbutyl)phenol

183 grams of 2,3-dimethylphenol, 168 grams of 2,4,4-trimethylpentene-1and 28.5 grams of p-toluenesulfonic acid monohydrate were added togetherto one liter of toluene, the reaction mixture being heated for 9 hoursat 80° to 85° C and 23 hours at 70° C. The reaction mixture was washedsuccessively with water, saturated sodium bicarbonate and water untilalmost neutral. After drying over anhydrous sodium sulfate, the driedreaction mixture was concentrated at reduced pressures to yield theintermediate (a) as a crude product. Unreacted 2,3-dimethylphenol wasremoved from the crude by sublimation at 70° to 75° C and 0.3 mm Hg.pressure. The residual liquid was then distilled to yield pure2,3-dimethyl-6-(1,1,3,3-tetramethylbutyl)-phenol boiling at 76° to 80°at 50 microns Hg. pressure.

b. The product was obtained by reacting2,3-dimethyl-6-(1,1,3,3-tetramethylbutyl)phenol with methyl acrylate ina similar manner as described in Example 1. The desired product wasobtained as white crystals melting at 83° to 85° C (Compound 2).

EXAMPLE 3 Methyl3-(5,6,7,8-tetrahydro-4-hydroxy-3-tert.-butylnaphthyl-1)propionate

a. 2-Tert-butyl-5,6,7,8-tetrahydro-1-naphthol

To a solution of 60 grams of 5,6,7,8-tetrahydro-1-naphthol and 5.7 gramsof p-toluenesulfonic acid monohydrate in 600 ml of toluene at 75° C wasbubbled in about 30 grams of isobutylene over a period of 3 hours. Thereaction mixture was then kept at 75° C for an additional hour. Aftercooling to room temperature, the reaction mixture was washedsuccessively with water, saturated sodium bicarbonate and with wateragain. The toluene phase was then dried over anhydrous sodium sulfate.After removing the solvent by distillation at reduced pressure, theresidue was distilled yielding2-tert-butyl-5,6,7,8-tetrahydro-1-naphthol as a light yellow viscousliquid boiling at 97°-98° C at 0.1 mm Hg.

b. Methyl 3-(5,6,7,8-tetrahydro-4-hydroxy-3-tertbutyl-naphthyl-1)propionate was obtaind by reacting5,6,7,8-tetrahydro-2-tert.-butyl-1-naphthol with methyl acrylate in ananalogous manner as described in Example 1. The compound was obtained aswhite crystals melting at 84° to 86° (Compound 3).

EXAMPLE 4 n-Octadecyl3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate

37.9 grams of n-octadecanol and 38.8 grams of the compound of Example 1were added to a reaction flask, dried and flushed with dry nitrogen.Then were added 1 ml of dry dimethyl sulfoxide and 56 milligrams oflithium hydride, the system flushed again with nitrogen and the reactionmixture heated to 120° C. The melt was then heated at 120° to 125° at 1atmosphere pressure for 1 hour, at 130° for 50 minutes at 1 atmosphereand finally at 130° to 140° at 20 mm Hg. for 1.25 hours. During thisperiod, 5.6 ml of methanol was collected. The reaction mixture wasdissolved in 200 ml of toluene, neutralized with 0.5 ml of glacialacetic acid. The toluene solution was then washed successively withaqueous saturated sodium chloride solution and dried over anhydrousmagnesium sulfate. The clear filtrate, after removal of drying agent,was concentrated at reduced pressures, the resulting residue being keptat 50° to 60° C and 0.3 mm Hg. for 1 hour to substantially remove allvolatile material, yielding a brown residual oil. After twocrystallizations from methanol-isopropanol mixtures, the desired productwas obtained as white crystals melting at 55° to 57° (Compound 4).

In an analogous manner to the procedure described in Example 4, theexamples shown in Table I were prepared.

                                      TABLE                                       __________________________________________________________________________    Other 3-(3-tert.-Alkyl-5,6-dialkyl-4-hydroxyphenyl)propionates                 ##STR14##                                                                    Compound No.                                                                          R           R.sup.1 R.sup.2 R.sup.3       n M.P.° C.           __________________________________________________________________________             ##STR15##  CH.sub.3                                                                              CH.sub.3                                                                              n-C.sub.18 H.sub.37SCH.sub.2 CH.sub.2                                                       1 49-51                     6                                                                                      ##STR16##  CH.sub.3                                                                              CH.sub.3                                                                               ##STR17##    1 87.5-89.5                 7                                                                                      ##STR18##  CH.sub.3                                                                              CH.sub.3                                                                               ##STR19##    1 liquid.sup.(1)            8                                                                                      ##STR20##  CH.sub.3                                                                              CH.sub.3                                                                              n-C.sub.18 H.sub.37                                                                         1 47-50                     9                                                                                      ##STR21##                                                                                 ##STR22##      n-C.sub.18 H.sub.37                                                                         1 59-61                     10                                                                                     ##STR23##  CH.sub.3                                                                              CH.sub.3                                                                               ##STR24##    2 116-119                   11                                                                                     ##STR25##  CH.sub.3                                                                              CH.sub.3                                                                              (CH.sub.2).sub.6                                                                            2 108-110                   12                                                                                     ##STR26##  CH.sub.3                                                                              CH.sub.3                                                                               ##STR27##    4 159-164                   13                                                                                     ##STR28##  CH.sub.3                                                                              CH.sub.3                                                                               ##STR29##    4 81-90                     __________________________________________________________________________     Note:                                                                         .sup.(1) Purified by silica gel treatment - pale yellow liquid           

EXAMPLE 5 5-tert-Butyl-2,3-dimethyl-4-hydroxyphenylacetic acid

a. 6-tert-butyl-2,3-dimethyl-4-(dimethylaminomethyl) phenol

To 142.4 grams of 6-tert.-butyl-2,3-dimethylphenol dissolved in 270 mlof toluene was added 144.4 grams of a 25% aqueous solution ofdimethylamine at about room temperature. 65.7 grams of 36.5% aqueousformaldehyde was then added over a ten minute period to the reactionmixture initially at 15°, the temperature rising to 30° at the end ofthe addition. The reaction mixture was then warmed to 40° for 3 hoursand finally heated at reflux (85°) for 2 hours. The reaction was dilutedwith about 1 liter of ether and the aqueous layer separated, the upperether layer being washed three times with water. After drying oversodium sulfate, the organic phase was stripped to dryness at reducedpressures yielding 176.3 grams of crude product. The crude product wascrystallized from heptane, yielding white crystals melting at 101° to104°.

b. 5-tert.-butyl-2,3-dimethyl-4-hydroxyphenylacetonitrile

To 48 grams of sodium cyanide dispersed in 900 ml ofN,N-dimethylformamide was added with vigorous stirring at 25° to 30° C asolution of 153 grams of the compound prepared in (a) above dissolved in200 ml of N,N-dimethylformamide. The reaction mixture was then heatedwith stirring at 70° to 75° for 5 hours. The reaction mixture was cooledto room temperature and about 1000 grams of ice-water was added. Afterseeding with some product nitrile crystals to allow the product tocrystallize completely, the resulting white crystalline precipitate wasfiltered. The filter cake was washed with warm water and dried in thevacuum oven at 70° C and 15 mm Hg. vacuum. The dried crystallineprecipitate was slurried with hot hexane to remove color bodies,yielding the nitrile product as white crystals melting at 126° to 128°.

c. 104 grams of the nitrile prepared in (b) was added slowly to amixture of 115.2 grams of 50% aqueos sodium hydroxide and 64 grams ofethylene glycol at 80°. The temperature was gradually increased to keepthe reaction product stirrable. After about 1 hour, reflux temperaturewas reached (120° C) and heating at reflux was continued for 6 hours.The reaction mixture was diluted with about 4 liters of water, warmed todissolve the sodium carboxylate salt, and filtered to remove a littleinsoluble material. The clear filtrate was acidified with concentratedhydrochloric acid, the precipitated product filtered, and the filtercakevacuum dried at 80° C at 15 mm Hg. pressure. The product was obtained asa white powder melting at 213° to 217° C. Crystallization fromacetonitrile raises the melting range to 214° to 218° C (Compound 26).

EXAMPLE 6 Methyl 5-tert.-butyl-2,3-dimethyl-4-hydroxyphenylacetate

11.8 grams of 5-tert.-butyl-2,3-dimethyl-4-hydroxyphenylacetic acid wasadded at 20° C to 200 ml of methanol previously saturated with hydrogenchloride gas. The slightly pinkish solution was heated at reflux (68° C)for 3 hours after which about one-half of the solvent was removed atreduced pressures and the reaction mixture then poured into about 500 mlof an ice-water mixture with stirring until all the ice had melted. Theprecipitated crystals were filtered, washed with water and dissolved inbenzene. The benzene solution was successively washed with water,saturated sodium bicarbonate solution and finally with water to pH 7,the benzene solution being dried over anhydrous sodium sulfate. Theclear benzene solution, freed of drying agent by filtration, wasconcentrated at reduced pressure. The resulting solid residue wastriturated with hexane to remove color bodies. After recrystallizationfrom methanol, the desired product was obtained as white crystalsmelting at 117° to 119° C (Compound 14).

EXAMPLE 7 n-Octadecyl 5-tert.-butyl-2,3-dimethyl-4-hydroxyphenylacetate

8.85 grams of 5-tert.-butyl-2,3-dimethyl-4-hydroxyphenylacetic acid,9.45 grams of n-octadecanol and 0.665 grams of p-toluenesulfonic acidmonohydrate were dispersed in 500 ml of toluene and heated at reflux forseven hours. A little ether was added to the cooled reaction mixture toprevent precipitation. The reaction solution was then successivelywashed with water, saturated sodium bicarbonate solution and water onceagain until neutral. After drying over anhydrous sodium sulfate andfiltering, the clear filtrate was concentrated at reduced pressures.After washing with cold acetonitrile, the dried ground residue wascrystallized from n-heptane yielding white crystals melting at 79° to81° (Compound 15).

In a similar manner to Example 7, other5-tert.-butyl-2,3-dimethyl-4-hydroxyphenylacetates were prepared asshown in Table II.

                  TABLE II                                                        ______________________________________                                        Other 5-tert.-butyl-2,3-dimethyl-4-hydroxyphenylacetates                       ##STR30##                                                                    Compound                                                                      No.       R.sup.3       n        M.P.° C                               ______________________________________                                        16        n-C.sub.4 H.sub.9                                                                           1        89-93                                        17        n-C.sub.8 H.sub.17                                                                          1        63-65                                        18        n-C.sub.12 H.sub.25                                                                         1        68-70                                        19                                                                                       ##STR31##    2        143-145                                      20        (CH.sub.2).sub.6                                                                            2        152-155                                      ______________________________________                                    

EXAMPLE 8 p-tert.-Octylphenyl3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate

A stirred mixture of3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionic acid (12.5 g.,0.05 mole) and thionyl chloride (7.5 g., 0.063 mole) in 250 ml of drytoluene containing a few drops of N,N-dimethylformamide was heated at75° to 85° for 1 hour, precautions being taken to exclude moisture.p-Tert.-octylphenol (10.3 g., 0.05 mole) was added, and the mixture wasstirred and refluxed for 18 hours. The solvent was evaporated underreduced pressure and the residue thus obtained was dissolved in ether.The ether solution was washed with 10% sodium carbonate solution andthen water. Evaporation of the sodium sulfate dried ether solutionafforded an oily residue which was dissolved in petroleum ether. Onstanding, a crystalline solid separated. Two recrystallizations of thematerial from hexane furnished the product as white crystals, m.p.104.5° to 106.5° C(Compound 21).

By employing a similar procedure to that shown in Example 8, thecompounds shown in Table III were prepared.

                  TABLE III                                                       ______________________________________                                        Other aryl 3-(5-tert.-butyl-2,3-dimethyl-                                     4-hydroxyphenyl)propionates                                                    ##STR32##                                                                    Compound   Structure        m.p.                                              No.        R.sup.3          ° C                                        ______________________________________                                        22                                                                                        ##STR33##       112-114                                           23                                                                                        ##STR34##       90-92                                             24                                                                                        ##STR35##       138-140                                           ______________________________________                                    

EXAMPLE 9 Neopentanetriyltris-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenylacetate)

24.2 grams of 5-tert.-butyl-2,3-dimethyl-4-hydroxyphenylacetic acid, 3.6grams of 1,1,1-trimethylolethane and 0.746 grams of dibutyltin oxidewere dispersed in 35 ml of dry xylene and 3 ml of dry dimethyl sulfoxideand heated to distill out xylene solvent until a reflux temperature of152° to 155° was reached. The reaction mixture then became homogeneousand was heated with stirring at this temperature for 18 hours, and thenfor an additional 6.5 hours at 157°-160°. The reaction mixture wasdissolved in 800 ml chloroform and successively washed with water,saturated aqueous sodium bicarbonate solution and again with water untilthe pH of the water water was neutral. The reaction solution was thendried over anhydrous sodium sulfate. Th clear filtrate was evaporated atreduced pressures yielding a residue which became crystalline ortrituration with a boiling mixture of 80 ml of hexane and 70 ml oftoluene. After successive crystallizations from isopropanol and thentoluene, the product was obtained as white crystals melting at 159°.164°(Compound 25).

By a procedure similar to Example 9, the compounds presented in Table IVwere prepared.

                  TABLE IV                                                        ______________________________________                                         ##STR36##                                                                    Compound                                                                      No.     x     n     R.sup.3     M.P.° C                                ______________________________________                                        27      1     2     (CH.sub.2 CH.sub. 2).sub.2 S                                                              118-124                                       28      2     2     (CH.sub.2 CH.sub.2).sub.2 S                                                               viscous syrup.sup.(1)                         29      1     4                                                                                    ##STR37##  186-189                                       ______________________________________                                         Note:                                                                         .sup.(1) Purified by silica gel column chromatography yielding a light        yellow syrup.                                                            

EXAMPLE 10 2,2-Dimethyl-1,2,2-pentanetriyltris-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenylacetate)

A mixture of 2.54 grams of 1,1,1-trimethylolbutane together with 13.5grams of methyl 5-tert.-butyl-2,3-dimethyl-4-hydroxyphenylacetate and13.7 milligrams of lithium hydride was heated together under nitrogen at115° for 20 minutes, then 140° for 30 minutes, 170° for 1 hour, themixture then being held at 190° to 195° for 4 hours. During this heatingcycle the evolved methanol was removed by distillation. After removal ofthe unreacted methyl 5-tert.-butyl-2,3-dimethyl-4-hydroxyphenylacetateby distillation at reduced pressures, the residue was dissolved inbenzene and the benzene solution was acidified with 1 ml of acetic acid.The benzene solution was freed of a small amount of insoluble materialby filtration. The benzene solution containing product was then washedwith 5% aqueous sodium carbonate and dried over sodium sulfate yieldingthe product in crude form as a glassy residue. After purification bydry-column chromatography using silica gel, the product was obtained aswhite crystals melting at 73° to 75° C after crystallization from asolvent mixture of benzene-hexane (Compound 30).

EXAMPLE 11 3,6-Dioxa-1,8-octamethylenebis-{3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate}

a. 3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl) propionic acid

Under nitrogen, a solution of methyl3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate (71.5 g) in 150ml of ethanol was treated with a solution of 98% sodium hydroxide (12.1g) in 15 ml of water, and the mixture was heated under reflux for 3hours. The cold solution was diluted with water to about 1200 ml andthen acidified with concentrated hydrochloric acid. The precipitatedsolid was filtered off and washed with water. Recrystallization from 600ml of acetonitrile gave the acid, m.p. 191° to 193° C.

b. A stirred mixture of 12.0 grams of3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionic acid, 3.0 gramsof triethylene glycol and 0.6 milliliters of titanium tetraisopropylatein 200 ml of dry xylene was heated at reflux for 18 hours, the evolvedwater being removed by azeotropic distillation. The xylene was removedby distillation at reduced pressures and the residue obtained taken upin ether. The ether solution was clarified by filtration and dried oversodium sulfate after removal of the drying agent by distillation atreduced pressures. The product was purified by dry-column chromatographyusing silica gel as absorbent. The product was obtained as a colorlessglass (Compound 31).

EXAMPLE 12 Ethylenebis-{3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate}

This compound was prepared in a similar manner by substituting ethyleneglycol for triethylene glycol in Example 11. After crystallization froma solvent mixture of benzene-heptane, the product was obtained as whitecrystals melting at 148° to 150° (Compound 32).

Unstabilized polypropylene powder (Hercules Profax 6501) was thoroughlyblended with 0.2% by weight of the indicated stabilizer compound. Alsoprepared were samples of polypropylene containing 0.1% by weight of thesame stabilizer and 0.3% by weight of distearyl β-thiodipropionate(DSTDP). The blended materials were then milled on a two-roll mill at182° C for 10 minutes, after which time the stabilized polypropylene wassheeted from the mill and allowed to cool.

The milled polypropylene sheets were then cut into pieces and pressedfor 7 minutes on a hydraulic press at 218° C, 19.25 Kg/cm² pressure. Theresulting plaques of 0.635 mm thickness were tested for resistance toaccelerated aging in a forced draft oven at 150° C. When the plaquesshowed the first signs of decomposition (e.g., cracking or brown edges)they were considered to have failed. The results are shown in Table Vbelow.

                  TABLE V                                                         ______________________________________                                        Oven Aging of Polypropylene Plaques                                           Containing 2,3,5-Trialkyl-4-hydroxyphenyl Alkanoates                          Ex.                                                                           No.   Percent Stabilizer    Hours to Failure                                  ______________________________________                                        13    Unstabilized          3                                                 14    0.2% Compound 16      < 20                                              15    0.1%"16 + 0.3% DSTDP  205                                               16    0.2%"17               < 20 -17 0.1%"17 + 0.3% DSTDP 220                 18    0.2%"18               < 20                                              19    0.1%"18 + 0.3% DSTDP  250                                               20    0.2%"15               45                                                21    0.1%"15 + 0.3% DSTDP  215                                               22    0.2%"4                55                                                23    0.1%"4 + 0.3% DSTDP   1070                                              24    0.2%"2                < 20                                              25    0.1%"2 + 0.3% DSTDP   155                                               26    0.2%"8                25                                                27    0.1%"8 + 0.3% DSTDP   1110                                              28    0.2%"3                < 20                                              29    0.1%"3 + 0.3% DSTDP   200                                               30    0.2%"9                175                                               31    0.1%"9 + 0.3% DSTDP   795                                               32    0.2%"7                <20                                               33    0.1%"7 + 0.3% DSTDP   115                                               34    0.2%"6                < 20                                              35    0.1%"6 + 0.3% DSTDP   110                                               36    0.2%"21               25                                                37    0.1%"21 + 0.3% DSTDP  205                                               38    0.2%"24               < 20                                              39    0.1%"24 + 0.3% DSTDP  125                                               40    0.2%"23               < 20                                              41    0.1%"23 + 0.3% DSTDP  150                                               42    0.2%"22               < 20                                              43    0.1%"22 + 0.3% DSTDP  140                                               44    0.2%"19               45                                                45    0.1%"19 + 0.3% DSTDP  250                                               46    0.2%"10               190                                               47    0.1%"10 + 0.3% DSTDP  1590                                              48    0.2%"20               25                                                49    0.1%"20 + 0.3% DSTDP  1130                                              50    0.2%"11               240                                               51    0.1%"11 + 0.3% DSTDP  2270                                              52    0.2%"25               75                                                53    0.1%"25 + 0.3% DSTDP  2520                                              54    0.2%"29               75                                                55    0.1%"29 + 0.3% DSTDP  2100                                              56    0.2%"12               105                                               57    0.1%"12 + 0.3% DSTDP  1510                                              58    0.2%"27               140                                               59    0.1%"27 + 0.3% DSTDP  965                                               60    0.2%"28               480                                               61    0.1%"28 + 0.3% DSTDP  1225                                              62    0.2%"13               190                                               63    0.1%"13 + 0.3% DSTDP  1545                                              64    0.2%"5                1005                                              65    0.1%"5 + 0.3% DSTDP   1750                                              66    0.2%"30               80                                                67    0.1%"30 + 0.3% DSTDP  1760                                              68    0.2%"31               215                                               69    0.1%"31 + 0.3% DSTDP  1195                                              70    0.2%"32               110                                               71    0.1%"32 + 0.3% DSTDP  590                                               ______________________________________                                    

The stabilizers are particularly effective in the presence of a thioester co-stabilizer such as DSTDP.

EXAMPLE 72

Pellets (500 g) of unstabilized nylon-6,6 (Zytel 101, DuPont) are placedin a Kitchen Aid Mixer. With mixing a solution of 0.5% (based on theweight of nylon) of n-octadecyl3-(5-t-butyl-2,3-diethyl-4-hydroxyphenyl)propionate in 20 ml ofmethylene chloride is added slowly. Sodium hypophosphite (0.5 gm 0.1%)is dissolved in 20 ml of water and added slowly with mixing to the nylonpellets after the antioxidant solution has been added and most of themethylene chloride has evaporated. The stabilized pellets are dried at80° C at <<1 mm Hg. for 4 hours.

The polyamide formulation is extruded at 315.6° C through a 0.635 cm dieinto a rod which is water cooled and chopped into pellets. A 1.905 cmBrabender extruder, equipped with a nylon screw, is used. The pelletsare dried at 80° C at <1mm for 4 hours.

The dried pellets are compression molded into 0.127 mm thick film bypressing at 290° C for 4 minutes at 57.75 Kg/cm². The films are ovenaged at 150° C in a forced draft oven and samples are removedperiodically. The specific viscosity of the samples are determined usinga 1% formic acid solution at 25° C. The sample stabilized with the abovenoted stabilizer required longer aging time to reduce its viscosity byone-half than the unstabilized sample.

EXAMPLE 73

Unstabilized high impact polystyrene resin is dry blended with 0.01% byweight of the resin of 2-(n-octylthio)ethyl5-t-butyl-2,3-dimethyl-4-hydroxyphenylacetate. The resin is thenextrusion compounded on a 2.54 cm 24/1=L/D extruder, melt temperature260° C and pressed for 7 minutes at a temperature of 163° C and apressure of 140 Kg/cm² into a sheet of uniform thickness of 2.54 mm. Thesheets are then cut into plaques of 5.08 cm × 5.08 cm. The plaques arethen oven aged at 80° C and color measurements made periodically using aHunter Color Difference Meter Model D25. The polystyrene samplesstabilized with the above stabilizer develops the undesirable yellowdiscoloration substantially later than the time that such discolorationoccurred in the unstabilized samples.

EXAMPLE 74

Unstabilized linear polyethylene (HiFax 4401) is solvent blended inmethylene chloride with 0.2% by weight of the substrate of ethylenebis[3-(5-isopropyl-2,3-dimethyl-4-hydroxyphenyl)propionate] and thenvacuum dried. The resin is then extruded at 232.5° C using a 1.905 cmextruder having a 24:1 L/D ratio. The melt flow rate of a sample of theresin is determined after each extrusion according to ASTM test D-1238.Polyethylene stabilized with above compound is found to undergo lesschange in the melt flow rate than the unstabilized polyethylene.

EXAMPLE 75

A quantity of SBR emulsion containing 100 g of rubber (500 ml of a 20%SBR emulsion obtained commercially from Texas U.S. as Synpol 1500)previously stored under nitrogen, is placed in a beaker and stirredvigorously. The pH of the emulsion is adjusted to 10.5 with a 0.5N NaOHsolution.

To the emulsion is added 50 ml of 25% NaCl solution. A 6% NaCl solutionadjusted with hydrochloric acid to a pH 1.5 is added in a thin streamwith vigorous stirring. When pH 6.5 is reached, the rubber begins tocoagulate and the addition is slowed down in order to maintain uniformagitation. The addition of the acidic 6% NaCl solution is terminatedwhen a pH 3.5 is reached. The coagulated crumbrubber slurry at pH 3.5 isstirred for 1/2 hour.

The coagulated rubber is isolated by filtration through cheese cloth,and rinsed with distilled water. After three subsequent washings withfresh distilled water, the coagulated rubber is dried, first at 25 mm Hgand finally to constant weight under high vacuum (< 1 mm) at 40° to 45°C.

The dried rubber (25 g) is heated under nitrogen at 125° C in aBrabender mixer and to this is added with mixing 0.1% of1,8-octamethylene bis-[4-(2,3,5-trimethyl-4-hydroxyphenyl)butyrate].

Portions of the rubber are oven aged at 100° C. At various intervals gelcontent is determined on the rubber. The rubber stabilized with theabove compound shows much less gel formation than the unstabilizedsample.

EXAMPLE 76

To 50 g of polyacetal resin containing 0.1% of an acid scavenger,dicyandiamide, is added 0.2% by weight ofphenyl(5-t-octyl-2,3-dimethyl-4-hydroxy-phenyl)acetate, and milled for 7minutes at 200° C in a Brabender Plastirecorder. The milled formulationis subsequently pressed into a 1.016 mm sheet at 215° C at 24.5 Kg/cm²for 90 seconds then cooled quickly in a cold press at 24.5 Kg/cm². Thestabilized sheets are then remolded for 2 minutes at contact pressureand for 3 minutes at 21 Kg/cm² at 215° C to give plaques 3.81 cm × 5.715cm × 3.175 mm. The plaques are aged in the oven at 60° C and the weightloss of the specimen is determined periodically until a 4% weight lossis reached. The stabilized sample takes a much longer time to reach this4% weight loss than does the unstabilized sample.

EXAMPLE 77

Unstabilized, thoroughly dried polyethylene terephthalate chips are dryblended with 1.0% of 3,6-dioxa-1,8-octamethylenebis-[3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate]. 60/10 deniermultifilament is melt spun at a melt temperature of 290° C and coldoriented 3 to 1. The oriented fibers are wound into skeins and oven agedat 140° C. The stabilized material exhibits greater retention of tensilestrength after 24 hours than the unstabilized material.

EXAMPLE 78

A stabilized high temperature lubricating oil is prepared byincorporating 0.05% by weight of 2,2-dimethyl-1,2,2-pentanetriyltris-[3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate] to thelubricant which comprises diisoamyl adipate. The stabilized compositionis compared with the unstabilized lubricant by heating at 175° C in thepresence of air and metallic catalysts according to the test methoddescribed in Military Specification Mil-I-7808c. After 72 hours, theblank containing no stabilizer contains more sludge and has a greaterviscosity than the stabilized lubricant.

EXAMPLE 79N-Methyl-3-(2,3-dimethyl-5-tert.-butyl-4-hydroxyphenyl)propionamide

A mixture consisting of 450 ml of dimethyl sulfoxide 29.4 g methylamine,and 5.04 g of a 57% oil dispersion of sodium hydride (=0.1197 moles) wasstirred at 25° C for 31/4 hours. 15.1 g methyl3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate was then addedand the resulting mixture stirred 18 hours at 25° C. The reactionmixture was then neutralized with 1 glacial acetic acid, diluted withwater, and extracted with ether. The ether extracts were combined andwashed with sodium hydroxide and water and dried over anhydrous sodiumsulfate. After removal of the ether by distillation, crystallization ofthe residue from toluene yielded white crystals melting at 125° to 128°(Compound 33).

EXAMPLE 80N-Methyl-N-n-octadecyl-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)acetamid

A mixture consisting of 8.76 g of methyl2,3-dimethyl-5-t-butyl-4-hydroxyphenylacetate and 11.87 g ofN-methyl-N-n-octadecylamine was heated under nitrogen at 165° to 180°for 5 hours then at 180° to 187° for an additional 3 hours. The methanolof reaction was removed continuously by distillation. The product waspurified by two crystallizations from ethanol, and was obtained as awhite solid having melting point 99° to 102° C (Compound 34).

N-n-dodecyl-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)acetamide ismade by an analogous procedure by substituting n-dodecylamine forN-methyl-N-n-octadecylamine.

EXAMPLE 81N-n-Octadecyl-3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionamide

A mixture consisting of 10.6 grams of methyl3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate and 11.9 gramsof n-octadecylamine were heated together for 1 hour at 160° to 165° andthen at 175° to 180° for 4 hours, the methanol of reaction being removedcontinuously by distillation. Crystallization from methanol yieldedwhite crystals melting at 85° to 87° (Compound 35).

EXAMPLE 82N,N'-Ethylenebis-{3-(5-tert.-butyl-2,3-di-methyl-4-hydroxyphenyl)propionamide}

A mixture consisting of 22.21 grams of methyl3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate and 2.4 gramsof ethylenediamine were melted together and gradually heated from 91° to172° over a period of 18.5 hours and then maintained at 172° for anadditional 2 hours while removing the methanol of reaction bydistillation. The product was successively crystallized from a solventmixture of ethanol-water and then from acetonitrile to yield whitecrystals melting at 214° to 217° (Compound 36).

N,N'-1,2-propylenebis-{3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionamide}is made in a similar manner by substituting 1,2-propylenediamine forethylenediamine in the above procedure.

EXAMPLE 83N,N'-Hexamethylenebis-{3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionamide}

This product was made by a similar procedure as that described inExample 82 by substituting 1,6-hexanediamine for ethylenediamine. Aftersuccessive crystallization from a solvent mixture of carbontetrachloride-1,2-dichloroethane, methanol-water and finally fromchloroform, the product was obtained as white crystals melting at 176°to 178° (Compound 37).

N,N'-dodecamethylenebis-{3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionamide}ismade by a similar procedure to that described in Example 82 bysubstituting 1,2-dodecamethylenediamine for ethylenediamine.

EXAMPLE 84N,N'-Bis-{3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionyl}piperazine

A mixture consisting of 20.0 grams of methyl3-(5-tert.-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate and 3.1 gramsof piperazine was gradually heated from 120° to 175° over 6.5 hours andmaintained at 175° to 180° for an additional 4 hours in a nitrogenatmosphere while removing the methanol of reaction by distillation. Thereaction product was purified by repeated extractions with fresh hottoluene and finally with 95% ethanol to yield the purified product as awhite solid melting at 221° to 224° (Compound 38).

EXAMPLE 85N,N'-3,6-Dioxa-1,8-octamethylenebis-[3-(5-tert-butyl-2,3-dimethyl-4-hydroxyphenyl)propionamide]

A mixture consisting of 18.9 grams of methyl3-(5-t-butyl-2,3-dimethyl-4-hydroxyphenyl)propionate and 5.0 grams(0.034 moles) of 3,6-dioxa-1,8-octanediamine was heated under a nitrogenatmosphere for 71/2 hours during which time the temperature wasgradually raised from 135° to 175°. Heating was continued for 61/2 hourslonger at 175° to 180°. The methanol by-product weighed 20.53 g. Theproduct was purified by extractions with 5% hydrochloric acid and water.Final purification was achieved by means of chromatography using aluminaand chloroform. This afforded 4.9 grams of a white glass having meltingpoint 72° to 95° (Compound 39).

Oven aging tests were run on compounds 33 to 39 using the sameprocedures of sample preparation and evaluation as detailed for Table V.The results of these oven againg tests are listed in Table VI.

                  TABLE VI                                                        ______________________________________                                        Oven Aging of Polypropylene Plaques                                           Containing 2,3,5-Trialkyl-4-hydroxyphenyl Alkanamides                         Ex. No                                                                              Percent Stabilizer    Hours to Failure                                  ______________________________________                                        86    Unstabilized          3                                                 87    0.2% Compound 33      < 20                                              88    0.1%"33 + 0.3% DSTDP  165                                               89    0.2%"34               105                                               90    0.1%"34 + 0.3% DSTDP  735                                               91    0.2%"35               175                                               92    0.1%"35 + 0.3% DSTDP  950                                               93    0.2%"36               105                                               94    0.1%"36 + 0.3% DSTDP  750                                               95    0.2%"37               90                                                96    0.1%"37 + 0.3% DSTDP  780                                               97    0.2%"38               65                                                98    0.1%"38 + 0.3% DSTDP  1855                                              99    0.2%"39               100                                               100   0.1%"39 + 0.3% DSTDP  415                                               ______________________________________                                    

What is claimed is:
 1. A compound having the formula ##STR38## wherein Ris branched alkyl of 3 to 8 carbon atoms,R¹ and R² are alkyl of 1 to 3carbon atoms, and A is straight chain alkylene of 1 to 3 carbon atoms.2. A compound of claim 1 wherein R is a branched chain alkyl and R¹ andR² are straight chain alkyl.
 3. The compound of claim 1,N,N'-bis[3-(5-tert-butyl-2,3-dimethyl-4-hydroxyphenyl)propionyl]piperazine4. A compound according to claim 1 whereinR is tert-butyl, R¹ and R² aremethyl, and A is methylene or ethylene.